With "Habits of the House," the first novel of a planned trilogy, Fay Weldon capitalizes on the spectacular success of the PBS television series, "Downton Abbey." "Habits of the House" is set in 1899, 15 years prior to the action of the television show, but like the series it is a delightful delineation of Britain's rigid class system, a phenomenon that would change dramatically in the aftermath of World War I.

Weldon brilliantly captures the rituals above stairs and the gossip below stairs in the aristocratic London household at No. 17, Belgrave Square, the residence of the Earl of Dilberne (Robert), his wife, Lady Isobel, their two adult children, Rosina and Arthur, and a score of servants. It is Weldon's relentless, mischievous sense of humor that underpins this book.

Grace, Lady Isobel's private maid, is the novel's main servant character. "Her normal mode was to agree, receive information, and not comment on it." In noting that other households had attempted to poach her, Weldon writes: "Grace was a favorite. The poor tended to be misshapen and vengeful at worst, pimply and sullen at best, but Grace was tall, slim and fair and an excellent lady's maid, quick, reliable, clean and willing. She seemed to have an instinctive eye for fashion."

While Weldon presents Robert as a likable, easygoing gentleman, a prominent Tory in the House of Lords, it soon becomes evident that he suffers from character flaws -- failings that have smothered him deep in debt. His incessant gambling pushes his liabilities to a frightening level. Even worse, attracted by "a harebrained scheme," he has invested most of his wealth -- including his children's nest egg -- in a South African gold mine. Because the Boer War is raging, the mine is eventually sabotaged, looted and flooded, becoming worthless.

Like his father, Arthur is not entirely a person of probity. He keeps a mistress named Flora in "a pretty little house in Half Moon Street," a mere 10-minute walk from his home. As debt collectors hound them and tradesmen refuse their requests, Lord and Lady Dilberne agree that Arthur must marry soon and marry well to keep the family from bankruptcy.

They choose for their son a visiting American named Minnie O'Brien, the only child of a rich Chicago stockyard baron, "a man so busy making money that [he] had no time for style."

"My father sent me to Europe to buy a husband and a title," announces Minnie, "and he will pay generously." Unpredictably, Arthur and Minnie like each other. But as the plot unfolds we understand that Arthur's liaison with Flora is not the only deal breaker in the Arthur and Minnie courtship. Apparently, Minnie, too, has a checkered past.

"Habits of the House" is an absorbing and worthwhile read.

Katherine Bailey writes reviews for the Philadelphia Inquirer. Visit her website at katherinebaileyonbooks.com.